Question: Ishaan was assigned articles 50 through 80 for homework last week. If Ishaan read all of the articles he was assigned, how many articles did he read?
Answer: Instead of counting articles 50 through 80, we can subtract 49 from each number so we instead consider articles 1 through 31. We see that Ishaan read 31 articles. Notice that he read 31 and not 30 articles.